In an event site where a large number of people congregate, such as a theme park, fair ground, bazaar, exposition, shopping mall and restaurant court, it is not possible to determine the state of congestion of a particular spot in the site unless the visitor actually walks to the particular spot. Therefore, it often happens that the visitor takes a trip to a particular spot and finds the spot too congested for the visitor to enjoy the spot. The visitor is thus forced to take unnecessary trips and waste time in an effort to find a spot of his or her choice.
Street performances are often shown in designated areas in a fair ground or in a street from which automobiles are blocked off. Various street performers show their performances irregularly and in various spots within the designated areas. Such a ground or event site is typically not designed so as to allow a general view of the site, and it is not possible for a visitor to find if any particular performance will suit the visitor's liking or not until the visitor actually comes to the spot. For this reason, each visitor has to take a tour of the entire site before he or she is capable of deciding which performance to see so that much time and effort has to be wasted.
The recent advance in technology allows images to be transmitted to remote locations by using the Internet and mobile phones (see Japanese patent laid open publication No. 2001-320460, for instance). If such a technology is used, a user can be informed on the state of a certain remote location without actually traveling to this location so that the user is not required to aimlessly move about and waste time and effort. Also, because the visitors can move with definite aims in most part, the distribution of the people within the site can be favorably averaged, and congestions in localized areas can be avoided.